The letter dating from 1997 demolishes Vatican claims that they never instructed local bishops to withhold evidence form police about pedophiles.

It was signed by the late Archbishop Luciano Storero, Pope John Paul II's Apostolic Nuncio to Ireland.

The letter instructs Irish bishops that their new policy of reporting of suspected crimes "gives rise to serious reservations of both a moral and canonical nature."

Storero wrote that canon law "must be meticulously followed," IE keep it within the church.

How he wrote the word 'moral' about a plot to keep pedophiles from the law is astounding

He said bishops who did otherwise would face the "highly embarrassing" position of having their actions overturned on appeal in Rome.

"The letter is of huge international significance, because it shows that the Vatican's intention is to prevent reporting of abuse to criminal authorities. And if that instruction applied here, it applied everywhere," said Colm O'Gorman, director of the Irish chapter of human rights watchdog Amnesty International.

It is an amazing document, the smoking gun that shows the Vatican was in the forefront of efforts to allow pedophiles escape justice.